The disclosure proceeds from a hydraulically controlled accumulator-chamber valve according to the description below.
Patent specification U.S. Pat. No. 7,543,896 B2, for example, has disclosed a hydraulically controlled accumulator-chamber valve, in which, in the accumulator piston, a ball seat valve which is prestressed by spring is opened via a tappet. This takes place in the case of a balance of forces specified for the system between a spring prestressing force and a hydraulically active force. The actuation of the ball seat valve takes place via a cylindrical metallic tappet which is pressed into the accumulator piston. The accumulator piston also accommodates a sealing ring and a guide ring. A correspondingly prestressed compression spring is situated between the accumulator piston and the closure cover which is connected to the pump housing via a securing calked portion. The spring force acts counter to the hydraulically active force on the accumulator piston and, in the case of a surplus of the spring force, brings about a displacement of the accumulator piston/tappet combination in the opening direction of the accumulator-chamber valve. Here, the ball is moved out of the seat by the tappet and the accumulator-chamber valve is opened.
Laid-open specification DE 42 02 388 A1 describes, for example, a hydraulic brake system for a motor vehicle. The brake system which is described comprises a hydraulically controlled accumulator-chamber valve with a closing element which is prestressed via a first compression spring and seals a valve seat in a valve body, and with a tappet which is connected to an accumulator piston, which is loaded by a second compression spring, and presses the closing element out of the valve seat when there is a specified balance of forces between the spring prestressing forces and a hydraulically active force. In these constructions of accumulator-chamber valves, the sealing body of the valve which is closed in a spring-assisted manner is moved into the open position by a pin which is connected to the accumulator piston, as soon as the accumulator-chamber volume undershoots a threshold value, that is to say the accumulator piston approaches the stop.